激光测距中数字鉴相器的设计

相位法激光测距广泛应用于距离测量,尤其是短距离测量领域,测距系统的测量精度和速度主要取决于鉴相器的设计,为提高鉴相器的测量精度和速度,本文给出了一种新型数字鉴相器。通过加入反馈电路控制信号调制器,只需一组鉴相器即可实现激光发射信号与接收信号相位差的测量。调整CIC滤波器的参数,最大限度地提高滤波器输出信号的信噪比。对CORDIC算法进行优化,不仅扩展了测量范围,而且提高了测量精度和速度。本文使用Matlab对该数字鉴相器进行了性能评估,并在FPGA上实现了该数字鉴相器,与传统的数字鉴相器相比,测量精度和速度都有较大的提高,同时也降低了设计成本。

Design of digital phase discriminator for laser range finder

Phase-shift laser range finder is widely used in distance measurement,especially in short distance measurement. The accuracy and speed of the measurement mainly depend on the digital phase discriminator. In order to improve the accuracy and speed of the measurement,a new digital phase discriminator is presented in this paper. By adding a feedback circuit to control the modulator,the phase shift between the transmitting and receiving signals can be measured with only one digital phase discriminator,which can improve the speed and save the cost. By adjusting the parameters of CIC filter,the SNR of output signals can be maximized. By optimizing the CORDIC algorithm,the measuring range can be extended,and the accuracy and speed can be improved. The performance of the new digital phase discriminator was evaluated with Matlab. Finally,the digital phase discriminator was implemented on FPGA. Compared with the traditional ones,the accuracy and speed of the new digital phase discriminator are better.